Method for labeling images through a computer game

ABSTRACT

A methodology to determine the contents of an image uses an online game that is played by a large number of people at once. Each player may be randomly assigned a partner to form a pair. Partners do not know each other&#39;s identity and cannot communicate with one another. Players cannot see what their partners are typing, and the only thing the two partners have in common is an image that they can both see. One object of the game is to have each player type exactly what his or her partner is typing or has already typed. Once both players type the same string of words or letters, they receive a new image (the players are not required to type the string at the same time). The string upon which the two players agree is used as a label for that image. When trying to agree on a word, players may not be able to type certain specific strings of characters or “forbidden words”. When humans play the electronic game (online or over the Internet), they help computers determine the contents of images. If played by a large number of people, this game could provide a resource capable of classifying a vast portion of images on the World Wide Web. Because of the rules governing abstracts, this abstract should not be used to construe the claims.

REFERENCE TO RELATED APPLICATION

The disclosure in the present application claims priority benefits ofthe earlier filed U.S. provisional patent application Ser. No.60/483,976, titled “Method For Labeling Images Through A Computer Game,”filed on Jul. 1, 2003, the entirety of which is hereby incorporated byreference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

The invention in the present application was made under a grant from theNational Science Foundation grants CCR-0122581 and CCR-0085982. TheUnited States federal government may have certain rights in theinvention.

BACKGROUND

1. Field of the Disclosure

The present disclosure generally relates to labeling of images withwords and, more particularly, to a method to determine the contents ofan image through a computer game.

2. Brief Description of Related Art

There are millions of images on the World Wide Web portion of theInternet (conveniently referred to hereinbelow as “the Internet”) and itis important to have a method that can assign word descriptions to eachimage (so that the images can be searched and indexed, for instance).Writing a program that can automatically label images in any meaningfulway is still impossible. Even recognizing slightly distorted text—a muchsimpler sub-problem—is hard for current computer programs. To get aroundthis, image search engines on the World Wide Web label images accordingto file names: an image named “car.jpg”, for instance, is labeled as animage of a car. This method, though somewhat successful, is clearly notoptimal. First, there is no reason for anybody other than the person whooriginally posted the image file to name it accurately, and second, asingle file name is not enough to describe the contents of an image.Text appearing adjacent to the images in web pages can also be used asan aid in the labeling process, but most images have little or noassociated text, and even when such text is present it can be difficultto process and is oftentimes unstructured and misleading. Thus asignificant percentage of all images on the World Wide Web areincorrectly labeled and cannot be found through reasonable searchqueries.

A possible solution to this problem is manual labeling. Manually labeledimage databases such as the Corbis Collection and the Getty Images(which can be viewed at www.corbis.com and www.gettyimages.com,respectively) allow for very accurate search results. However, manuallyclassifying all images on the World Wide Web could be extremelyexpensive given the sheer volume of the image collection over theInternet (there are over 1 billion images on the World Wide Web at thistime).

Over the years there has been considerable artificial intelligence workin the area of automatic determination of the contents of images. Themost successful attempts learn from large databases of annotated images(annotations typically refer to the contents of the image, and arefairly specific and comprehensive). Some of these methods cluster imagerepresentations and annotations to produce a joint distribution linkingimages and words. Such methods can predict words for a given image bycomputing the words that have a high posterior probability given theimage. Other algorithms attempt to combine large semantic text modelswith annotated image structures. Though impressive, such algorithmsbased on computer learning do not work very well in general settings andwork only marginally well in restricted settings. For example, the workdescribed in Duygulu, P., Barnard, K., de Freitas, N., and Forsyth, D.A., Object recognition as machine translation: Learning a lexicon for afixed image vocabulary, (Seventh European Conference on Computer Vision,2002, IV 97-112) only gave reasonable results for 80 out of 371vocabulary words (the evaluation procedure in this study consisted ofsearching for images using the vocabulary words, and only 80 queriesresulted in reasonable images).

Another line of work that is relevant is one that attempts to findspecific objects within images. Schneiderman and Kanade (ObjectDetection Using the Statistics of Parts, International Journal ofComputer Vision, 2002), for instance, introduced a method to locatehuman faces in still photographs. Such algorithms are typicallyaccurate, but have not been developed for a wide range of objects.Additionally, combining algorithms for detecting different objects intoa single general-purpose classifier is a non-trivial task. Thus, even amethod that can produce reasonable labels (not necessarily good labels)for images in general is desirable.

SUMMARY

Millions of people around the world play computer games. The presentapplication introduces a game that is fin to play, and which can be usedto determine the contents of an image. The game may be deployed at oneor more popular gaming sites through which individual players can accessand play the game online (i.e., over the Internet).

In one embodiment, the present disclosure contemplates a method thatcomprises the following steps to be performed electronically: selectingat least two participants from a plurality of participants; presentingan image to each selected participant; and requesting each selectedparticipant to provide a description of the image.

In another embodiment, the present disclosure contemplates a method thatcomprises: providing access to an online electronic game to a pluralityof participants over a communication network; selecting two participantsfrom the plurality of participants; presenting an image to the selectedtwo participants so as to enable both of the selected participants toview the image; and receiving from each of the two selected participantsat least one content-identifying term for the image.

In a still further embodiment, the present disclosure contemplates amethod that comprises: providing an online electronic game to aplurality of participants; randomly selecting two participants from theplurality of participants; presenting an image as part of the electronicgame to enable the selected participants to view the image; andrequesting the two selected participants to agree on a term describingthe image.

The present disclosure relates to a two-player game that is meant to beplayed online by a large number of people at once. Each player israndomly assigned a partner. Partners do not know each other's identityand cannot communicate with one another. Players cannot see what theirpartners are typing, and the only thing two partners have in common isan image that they can both see. One object of the game is to have eachplayer type exactly what his or her partner is typing or has alreadytyped (e.g., both players must provide the same description of the imagethey are viewing). Once both players type the same string of words orletters, they get a new image (the players are not required to type thestring at the same time). The string upon which the two players agree isused as a label for that image. In one embodiment, partners have to“agree” on as many images as they can in a certain amount of time. Somewords might be restricted (e.g., although accurate, certain words arenot allowed to be used, such as words that have already been agreed uponby other players who have described the same image previously), i.e.,when trying to agree on a word, players may not be able to type certainspecific strings of characters or “forbidden words”.

BRIEF DESCRIPTION OF THE DRAWINGS

For the present disclosure to be easily understood and readilypracticed, the present disclosure will now be described for purposes ofillustration and not limitation, in connection with the followingfigures, wherein:

FIG. 1 illustrates a simplified view of a hardware configuration thatmay be used to facilitate the online image labeling game according toone embodiment of the present disclosure;

FIG. 2 shows an exemplary image that may be presented to players of theimage labeling game and several exemplary steps leading to an agreementupon a description of the image; and

FIG. 3 depicts an exemplary process flow diagram of the onlineimage-labeling game according to one embodiment of the presentdisclosure, including provisions for excluding “forbidden words.”

DETAILED DESCRIPTION

Reference will now be made in detail to some embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingfigures. It is to be understood that the figures and descriptions of thepresent disclosure included herein illustrate and describe elements thatare of particular relevance to the present disclosure, whileeliminating, for the sake of clarity, other elements found in typicalonline games or Internet-based program applications. It is noted at theoutset that the terms “connected”, “connecting,” “electricallyconnected,” etc., are used interchangeably herein to generally refer tothe condition of being electrically connected. It is noted further that,for the sake of brevity and convenience, the term “image” is usedhereinbelow to refer to not only static images, but also to sound clipsand video clips, either individually or in combination, depending on theimplementation of the online labeling game according to the presentdisclosure. That is, the methodology described hereinbelow to labelstatic images may also be used to provide content-identifying terms forsound clips and video clips as well.

FIG. 1 illustrates a simplified view of a hardware configuration 10 thatmay be used to facilitate the online image labeling game according toone embodiment of the present disclosure. The configuration 10 mayinclude a game host computer 12 connected to a plurality of participantcomputers 14-17 via a communication network 20. The host computer 12 maybe an individual server or a distributed computing platform operatingin, for example, a Microsoft Windows® environment. In an alternativeembodiment, instead of a Windows®-based operating system, the hostcomputer 12 may employ a Unix®-based or Linux®-based operating system asis known in the art. Similarly, there may be various types ofparticipant computers or computing units 14-17 connected to the network20. For example, some of the participant computers may operate onWindows® operating system, whereas others may use the Linux® operatingsystem, and still others may operate on the Palm® operating system. Someof the participant computers (e.g., computing units 16 and 17) may beconnected wirelessly to the communication network 20. The computingunits may be in the form of desktop or notebook computers, cell phones,or PDA's (Personal Digital Assistants). The exact type and configurationof the participant's computing unit is not relevant to the presentdisclosure. It is, however, preferred that the participant's computer beable to connect to the communication network 20 via suitable means andalso be able to communicate with the host computer 12 using a commonprotocol (e.g., TCP/IP (Transmission Control Protocol/Internet Protocol)for communication over the Internet) so as to enable the computer's useto participate in the online game-playing.

The communication network 20 may be any type of computer or datacommunication network. In one embodiment, the communication network 20is the Internet. In that embodiment, various participants mayinteractively play the image labeling game according to the presentdisclosure over the Internet 20. The set of program instructions orsoftware to facilitate such game playing may reside on the host computer12, which may execute the software to allow participant computers (and,hence, the participants themselves) to interact with one another (asdescribed hereinbelow) and also to interact with the host computer 12itself. In one embodiment, the software for the online game may bestored on a portable data storage medium (e.g., one or more floppydiskettes, compact discs, external hard drives, etc.) (not shown) andinstalled in the host computer 12 when needed. In that event, thesoftware, upon execution by the host computer 12, may configure the hostcomputer to facilitate the online game playing described hereinbelow.

In one embodiment, the host computer 12 may access a local database 22containing a large number of images to be labeled. The host 12 may pickindividual images from the database 22 and supply them to various gamepartners as described hereinbelow. Alternatively, the database 22 may bein a distributed form (i.e., residing at a plurality of websites or hostlocations) or may be created during run time. In the latterimplementation, the host computer 12 may access a number of Internetwebsites and randomly collect the images therefrom to be supplied to theparticipants. These images may then also be stored in the database 22along with corresponding content-identifying terms for the imagesreceived from the participants (as discussed below).

As mentioned hereinbefore, the image-labeling game according to thepresent disclosure is preferably a two-player game, but it is meant tobe accessed on-line and played by a large number of people at once.Furthermore, it is conceivable that, in one embodiment, more than twoplayers may also receive an identical image and “annotate” the image inthe manner similar to that described hereinbelow with reference to imagecontent identification by only two players. It is noted here that thetwo players or “partners” may be selected randomly from the group ofparticipants (who communicate to the host computer 12 via theirrespective computing units 14-17) playing the image-labeling gameaccording to the present disclosure. It is preferable that the twoplayers do not know each other's identity. Furthermore, the two playersin each selected pair of participants may not communicate (using theirrespective computers, for example) with each other. Additionally, it ispreferable that players should not be allowed to see what their partnersare typing, and the only thing two partners have in common is an imagethat they can both see.

One object of the game is to encourage or request a participant to guesswhat the participant's partner is typing. Once both players type thesame string (of text letters or words), the current image may be removedfrom their view and, instead, they may get a new image for contentidentification. FIG. 2 shows an exemplary image 24 that may be presentedto players of the image labeling game and several exemplary stepsleading to an agreement upon a description of the image. It is observedfrom FIG. 2 that the players need not type the strings simultaneously.For example, as shown in FIG. 2, the response from one player (e.g.,Player 2 in FIG. 2) may be time-wise delayed from that of the otherplayer in the pair. In FIG. 2, the two players continue guessing thecontent-identifying term for the image 24 until both of them guess thecommon term “camera.” Although Player 1 in FIG. 2 continues guessing anadditional term (“film”) after typing “camera,” the software of the gamemay ignore the additional term and conclude that a successful match hasbeen established for the term “camera” so long as there is an identicalguess received from Player 2, even though the response from Player 2 istime-delayed. That is, the game may store all the entries or guessesreceived from both of the players until a match occurs, regardless ofthe order in which the matching term has been guessed by both of theplayers. Thus, both of the players may not have to guess the identicalcontent descriptive term simultaneously to obtain a success at labelingthe image 24 at hand. After successful and timely completion of contentidentification, the present image 24 may be removed from the players'view and replaced with another image as discussed hereinbelow withreference to FIG. 3.

In one embodiment of the present image labeling methodology (asimplemented through an online electronic game), partners may have to“agree” on as many images as they can in a certain amount of time (e.g.,90 seconds). Since the players cannot communicate and do not knowanything about each other, the easiest way for both to type the samestring is by typing something related to the common image. It is noted,however, that the game does not have to ask the players to describe theimage: all the players know is that to agree on an image, they must“think like each other” and type the same string. The string thatplayers agree on may be used as a label for that image. All other wordsor strings that players enter may also be used as labels or to obtaininformation about the image.

FIG. 3 depicts an exemplary process flow diagram of the onlineimage-labeling game according to one embodiment of the presentdisclosure, including provisions for excluding “forbidden words.” Aftera player logs into the host computer 12 (using the player's orparticipant's respective computing unit) offering the image-labelinggame (block 26), the game software in the host computer 12 may randomlyassign a game partner (block 28) to the player as describedhereinbefore. The partner may be another similar player/game participantjust logging in, or a player in need of a partner to commence and playthe game. The partner assignment establishes a pair ofparticipants/players ready to participate in the image labeling game.The game control software may then commence a timer (block 30) for thecurrent pair of participants. Simultaneously with starting the gametimer (block 30), the software may select and retrieve (e.g., from thedatabase 22) a new image to be sent to the computer terminals of bothplayers so that the players can view an identical image on theircomputers (block 32). The software may also retrieve any “forbiddenwords” associated with the selected image (and may have been stored inthe database 22 along with the image) and may clear two data storagesets—set A for one player and set B for another player—that may beassigned to the two players in the pair to store imagecontent-identifying text entries/responses received from the playersduring the game.

As noted hereinbefore, some images may have “forbidden words” associatedwith them. Players should not type an image's forbidden words, norshould they type singulars, plurals or phrases related to the forbiddenwords. In any event, a forbidden word entered by a player may not beaccepted by the game control software, requiring the player to inputanother word in place of the forbidden word to continue playing thegame. In one embodiment, the “forbidden words” may be obtained from thegame itself—i.e., the first time an image is used in the game, it willhave no forbidden words; however, if the image is ever used again, itwill have one forbidden word: the word that resulted from the previousclassification by a previous pair of players. It is noted that forbiddenwords may not necessarily be actual words in any language. However,prohibited expletives or foul language may be considered part of the“forbidden words,” and hence not considered a valid entry by a player.The use of “forbidden words” may allow for quite specific labels. Forexample, the first time around, without any forbidden words, the labelof an image may be expected to be a very general one, like “man.”However, subsequent classifications dictated by previously entered“forbidden words” may become progressively more specific because, forexample, unable to use the term “man,” players may start giving answersabout how the man is dressed or what he is doing.

Referring again to FIG. 3, after retrieving and sending an identicalimage to both players, the game control software may monitor the timerto determine whether the predetermined time period (T) has elapsed(decision block 34). If the predetermined time duration (e.g., T=90seconds) has elapsed without obtaining an identical match between thecontent-identifying terms received from both the players, the gamecontrol software may check at decision step 36 whether one or both ofthe players have indicated to stop the game (e.g., by logging out of thegame, or by a prolonged period of inactivity). If the game is to beconcluded, then the software finishes the game and sends appropriategame conclusion message to both the players at block 38. However, if thegame is to be continued despite no timely matching responses from boththe players, the game control software may instruct the host computer 12to retrieve another image from the database 22 and send this new imageto the players' computer terminals (block 32). In this case, the olderimage may not be displayed to the players any more because the new imagemay replace the older image on a player's computer screen or otherdisplay terminal (e.g., a cell phone display or a PDA display). Thepaired players may then continue content identification of themost-recently received new image as indicated at blocks 40, 42, and 44in FIG. 3.

If the timer has not run out at step 34, the game control software maycontinue to wait for and receive the content-identifying texts from boththe players. At block 40, the software may receive the input text fromone of the players and store it in the database 22 in data storage set Aso long as the text does not contain any forbidden word(s). Similarly,at block 42, the software may receive the image content-identifyingentries from the other player and store the entries in the data storageset B so long as the entries do not contain any forbidden word(s). It isobserved here that so long as the timer value is less than thepredetermined time limit for content identification of the currentimage, the software may continue receiving text entries from one or boththe players as shown, for example, in FIG. 2, where Player 1 has inputmore entries than Player 2 before a match is established. That is, aplayer may input his/her entries regardless of whether the player'spartner has input any corresponding entry. The player may not need towait for the partner's response to enter his/her strings. In oneembodiment, the players may be allowed to agree on and remotely set thetime limit (T) per game. In that event, the software may accept thevalue of T indicated by the players and start/stop the timeraccordingly.

At the decision block 44, the game control software continually comparesthe input strings stored in sets A and B to check whether any of thestring pairs intersect, i.e., whether there is an identical stringreceived from each of the two players. In the absence of the identicalmatch, the software may continue to receive more entries from theplayers, so long as the timer has not run out (as indicated by theprocess loop between blocks 44 and 34). On the other hand, if there isan identical entry stored in both sets A and B, then the software maydetermine that a match has been found and, hence, may conclude the gameof content identification of the present image and may continue the gamewith a new image so long as the “Game Over” indication is absent, asindicated by the process loop between blocks 36 and 32. The game maythus continue for each new image and for each pair of participatingplayers.

It may be desirable that the images used by the game be interesting tothe participants. For example, the game may perhaps be less entertainingif all the images were chosen from a single website containing second bysecond shots of an almost still scene. Similarly, different people mayenjoy playing with different sets of images, and several images foundonline may not be appropriate for all audiences. Such issues should beconsidered when writing a full-scale implementation of the game. In themost basic setting, the images may be chosen at random from the WorldWide Web with a small amount of filtering: no blank images, no imagesthat consist of a single color, no images that are smaller than 4×4pixels, etc. More specific “theme rooms” may be created for those whowish to play the game using only certain types of images. Some playersmay want images coming from certain domains or with specific types ofcontent. Such selection options may be provided to players in “themerooms.” Images for these “theme rooms” may be obtained either using webdirectories or the classifications given by the “general category”game—i.e., the classifications obtained as part of the basic imagelabeling game offered to all participants, regardless of theirsophistication or advanced status.

In one embodiment, the online image labeling game according to thepresent disclosure may be offered to participants either for free or fora nominal charge (in the form of, for example, a monthly subscriptionfee to the game-offering website, a flat fee for a fixed amount of gameplaying time (e.g., 60 minutes), or a charge per game). In analternative embodiment, to encourage participation of a larger audience,the game hosting website may offer “reward” to participants in terms of,for example, game points redeemable for select online merchandise orsouvenirs offered by the host website. Furthermore, to maintainparticipants' continued interest in the game, the host website may offeronline image-labeling tournaments or team activities to determinewinning players who “agree” on the most number of images in the shortesttime interval. Other business objectives may be used to publicize thegame and make it a success.

It is noted here that although the online labeling game has beendescribed hereinabove with reference to two players, the game may bedevised in a single player version. In that embodiment, a single playercan play with a pre-recorded set of actions as his/her “partner.” Thisset of actions may be recorded at an earlier time when two other peoplewere playing the game simultaneously. For each image, every guess ofeach partner in the earlier pair of players may be recorded, along withtiming information. Thereafter, whenever a single player wants to playthe game, the player may be paired with a pre-recorded set of actions.In this approach, the single player is basically playing with somebodyelse, but not at the same time. Each guess/input from the single playermay be responded with a guess in the pre-recorded set until a match isfound.

As noted before, automatic determination of the contents of an image maybe a problem far from being solved by computer vision techniques. Thus,the foregoing describes a methodology that introduces a simpleelectronic game that is fun to play and is able to harness humanresources to obtain content identification or labeling of a large numberof images online. When humans play the game online (or over theInternet), they help computers determine the contents of images. Ifplayed by a large number of people, this game could provide a resourcecapable of classifying a vast portion of images on the World Wide Web.The image labeling game according to the present disclosure representsan interaction between humans and computers, a symbiosis in which humansplaying the game are entertained and computers running the game obtainanswers to problems they may not be able to solve efficiently.

While the disclosure has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made therein withoutdeparting from the spirit and scope of the embodiments. Thus, it isintended that the present disclosure cover the modifications andvariations of this disclosure provided they come within the scope of theappended claims and their equivalents.

1. A method comprising the following steps to be performedelectronically: selecting at least two participants from a plurality ofparticipants; presenting a first image to each selected participant; andrequesting each said selected participant to provide a description ofsaid first image.
 2. The method of claim 1, wherein said selecting isperformed randomly.
 3. The method of claim 1, wherein said descriptionis a written text input electronically by each selected participant. 4.The method of claim 1, wherein said selecting includes: pairing two ofsaid plurality of participants as partners without disclosing anidentity of one partner to the other; preventing communication betweeneach paired partners; and further preventing each partner from receivingsaid description of said first image provided by the other pairedpartner.
 5. The method of claim 1, wherein said presenting includes:accessing a database storing a plurality of images; and selecting one ofsaid plurality of images to be presented as said first image to eachsaid selected participant.
 6. The method of claim 5, wherein selectingone of said plurality of images includes randomly selecting said one ofsaid plurality of images in said database as said first image.
 7. Themethod of claim 1, further comprising: storing said description of saidfirst image provided by each said selected participant; continuallycomparing stored descriptions received from each said selectedparticipant for similarity; and presenting a second image to each saidselected participant when corresponding description of said first imagereceived from each said selected participant is identical.
 8. The methodof claim 7, wherein presenting said second image includes removing saidfirst image from the view of each said selected participant.
 9. Themethod of claim 1, further comprising: requiring each said selectedparticipant to exclude at least one of the following from saiddescription of said first image: a word that has already been used aspart of said description of said first image; a textual variationrelated to said word; and a forbidden term.
 10. A method, comprising:providing access to an online electronic game to a plurality ofparticipants over a communication network; selecting two participantsfrom said plurality of participants; presenting a first image to saidselected two participants so as to enable both of said selectedparticipants to view said first image; and receiving from each of saidtwo selected participants at least one content-identifying term for saidfirst image.
 11. The method of claim 10, wherein said providing includesone of the following: offering said online electronic game on asubscription-basis to said plurality of participants; and charging twoor more of said plurality of participants on a per-game basis for saidonline electronic game.
 12. The method of claim 10, wherein saidcommunication network is the Internet.
 13. The method of claim 12,wherein said providing includes: hosting said online electronic game ata website on the Internet; and allowing each said participant to accesssaid website using a computing unit.
 14. The method of claim 10, whereinsaid selecting includes: pairing two of said plurality of participantsas partners without disclosing an identity of one partner to the other;preventing online communication between each paired partners; andfurther preventing each partner from receiving said content-identifyingterm provided by the other paired partner until a samecontent-identifying term is received from both of said selectedparticipants.
 16. The method of claim 10, wherein said presentingincludes: accessing a database storing a plurality of images over saidcommunication network; and selecting one of said plurality of images tobe presented as said first image to each of said two selectedparticipants.
 17. The method of claim 16, wherein selecting one of saidplurality of images includes randomly selecting said one of saidplurality of images.
 18. The method of claim 10, wherein saidcontent-identifying term is a written text.
 19. The method of claim 10,further comprising: storing online said content-identifying term forsaid first image provided by each of said two selected participants;continually comparing stored terms received from each of said twoselected participants for a match; and presenting a second image as partof said electronic game to said selected two participants uponoccurrence of one of the following: a corresponding content-identifyingterm for said first image received within a predetermined time periodfrom each of said two selected participants is identical, and saidpredetermined time period has elapsed without receiving an identicalcontent-identifying term from each of said two selected participants.20. The method of claim 19, wherein presenting said second imageincludes removing said first image from the view of both of saidselected participants.
 21. The method of claim 10, further comprising:requiring each said selected participant to exclude at least one of thefollowing from corresponding content-identifying term for said firstimage: a word that has already been used as part of said correspondingcontent-identifying term for said first image; a textual variationrelated to said word; and a forbidden term.
 22. A method, comprising:providing an online electronic game to a plurality of participants;randomly selecting two participants from said plurality of participants;presenting an image as part of said electronic game to enable theselected participants to view said image; and requesting the twoselected participants to agree on a term describing said image.
 23. Themethod of claim 22, wherein said requesting includes: inviting each ofsaid two selected participants to input an identical term for said imagewithin a predetermined time.
 24. A method comprising the following stepsto be performed electronically: randomly selecting two participants froma plurality of participants; presenting a first image to each of saidtwo selected participants; receiving from each of said two selectedparticipants at least one content-identifying term for said first image;requiring each of said two selected participants to exclude a forbiddenterm from a corresponding content-identifying term for said first imagereceived from each of said two selected participants; and removing saidfirst image from the view of both of said selected participants andpresenting a second image to said selected two participants uponoccurrence of one of the following: said correspondingcontent-identifying term for said first image received within apredetermined time period from each of said two selected participants isidentical, and said predetermined time period has elapsed withoutreceiving an identical content-identifying term from each of said twoselected participants.
 25. A data storage medium containing programinstructions, which, when executed by a processor, cause said processorto perform the following: provide an electronic game to a plurality ofparticipants; select two participants from said plurality ofparticipants; present an image as part of said electronic game to enablethe selected participants to view said image; and request the twoselected participants to agree on a term describing said image.
 26. Thedata storage medium of claim 25, wherein said program instructions, uponexecution, cause said processor to further perform the following: inviteeach of said two selected participants to input an identical term forsaid image within a predetermined time.
 27. A method comprising thefollowing steps to be performed electronically: selecting a firstparticipant and a second participant from a plurality of participants;presenting an image to each of said first and said second participants;requesting each of said first and said second participants to provide aplurality of terms describing said image; recording a set containingeach term provided by each of said first and said second participants;presenting said image to a third participant from said plurality ofparticipants; pairing said third participant with said set of inputs;requesting said third participant to provide a content-identifying termfor said image; and randomly supplying to said third participant adifferent input from said set of inputs in response to eachcontent-identifying term for said image supplied by said thirdparticipant.
 28. The method of claim 27, further comprising: declaring amatch when an input supplied to said third participant is identical to acontent-identifying term supplied by said third participant.